Combustible shell base

ABSTRACT

A combustible cartridge with an electric primer in which the bottom portion of the cartridge composed of combustible synthetic material with a plurality of annular surfaces arranged in different planes relative to one another and a primer is provided in the bottom portion.

United States Patent lnventors Paul Zehfeld llutlenstrasse 82, Dusseldorf; Hans-Dieter llarnau, Feldstrasse 2, Gevelsberg, Germany Appl. No. 796,956 Filed Feb. 6, 1969 Patented May 11, 1971 Priority Nov. 17, 1965, May 14, 1966 Germany P 12 91 262.8-15 and P 15 78 204.4 Continuation-impart of application Ser. No. 594,565, Nov. 15, 1966. 4

COMBUSI'IBLE SHELL BASE 4 Claims, 2 Drawing Figs.

US. Cl 102/44, 102/46 Int. Cl F42b 9/28 FieldofSearch 102/38, 39,

[56] References Cited UNITED STATES PATENTS 699,256 5/ l 902 Stockett 89/ 28 876,510 l/l908 Wheeler.... 89/28 1,081,983 12/1913 Pedersen... 102/44 2,117,885 5/1938 Hasek l02/44X 3,114,290 12/ 1 963 Harvey et a]... 89/26 3,169,333 2/1965 Scanlon, Jr. 42/69 3,446,1 13 5/ 1969 Dardick 89/2'6 Primary Examiner-Robert F. Stahl Attorney-Watson, Cole, Grindle & Watson ABSTRACT: A combustible cartridge with "an electric primer in which the bottom portion of the cartridge composed of combustible synthetic material with a plurality of annular surfaces arranged in difi'erent planes relative to one another and a primer is provided in the bottom portion.

COUSTlllBLE SHELL BASE This. application is a continuation-in-part of Ser. No. 594,565 filed Nov. 15, 1966.

The invention relates to a combustible cartridge bottom structure provided with an electric primer.

Combustible cartridge bottoms portions made of paper or synthetic material with a mechanical or electrical ignition means have been known. Their advantages consist therein, that empty cartridge shells will not pile up in limited spaces, for example, in tanks, as was the case hitherto with the use of metal cartridges. Further advantages lie in the utilization of gases obtained in the case of combustion in favor of a higher muzzle velocity.

Because such cartridge bottom parts consist of light and flexible substances, they have the definite disadvantage, that the resistance necessary for a reliable ignition or firing, as compared to that of an ignition pin or ignition contact, is not always guaranteed, as a result of which duds very frequently occur. At the same time, it is inconsequential whether the pressure on the primer is exerted by a mechanically operated firing pin or a firing contact being influenced by electric voltage.

The present invention has for an object to create a combustible cartridge bottom part provided with an electric primer, while avoiding the mentioned disadvantages, the bottom portion developing a resistance against a firing contact of the weapon with the resistance being provided by the resiliency of the cartridge bottom portion.

A further object of the invention that is solved by the fact, that the cartridge bottom portion consists of an easily combustible synthetic substance with several circular surfaces, which have been arranged in different planes in relation to one another and have been developed resiliently in such a manner, that the primer will oppose a resistance corresponding to the spring power of the cartridge bottom to the firing contact on the weapon.

The cartridge bottom has a central opening which extends inwardly in the shape of a casing. This opening is followed first by a funnel-shaped annular surface, then by a groove in the manner of an annular depression and finally by a plane bottom surface, which ends in a sector-shaped end surface in a cylindrical part of the casing. The individual surfaces have been connected with one another by bent edges.

The central opening serves for the reception and guidance of the primer, whereby the bent edge, connecting the central opening and the funnel-shaped annular surface, serves as a stop to the primer provided with a collar or flange.

So that a contact of the mass of the primer with the chamber of the gun is established, provision has been made to insert a metal band connected with the primer into the central opening, which band extends by means of the cartridge bottom up to a ring made of metal foil fitting from the outside against a part of the casing. A very special advantage of this resilient cartridge bottom results from cooperation with a locking wedge movable transversely to the axis of the gun into the chamber of the gun, whenever said wedge, following a slanting plane, strikes the primer with its firing contact and ignites the latter.

As a result of the fact that the cartridge bottom with the primer inserted therein opposes a resistance to the firing contact of the closing wedge, a faultless ignition is achieved.

Further objects will be apparent from the following description when considered in connection with the accompanying drawing in which;

FIG. 1 is a cross section showing a cartridge bottom inserted in the chamber of a gun barrel with opened breach, and

FIG. 2 is a cross section showing the cartridge bottom of FIG. 1 with a closed breach.

The gun barrel at its rear part has a gun chamber 1 which received the projectile and the cartridge charge 2. At the same time, as is known per se, the cartridge charges 2 can be inserted into the chamber 1 of the barrel either without a casing or by means of a cartridge casing or together with a projectile in the form of a round of ammunition consisting of one piece.

The embodiment shown by way of example deals only with the cartridge bottom 3, where a short cylindrical part 12 of the casing follows merely for a better placing or fit of its seat in chamber 1 of the gun.

In the middle of the cartridge bottom 3 there is a central opening 4, which has been prolonged inwardly in the form of a casing. The central opening 4 broadens by means of a bent edge 5 toward the outside to a funnel-shaped annular surface 6, which in turn ends in a bent edge 7. From here, the cartridge bottom 3 again proceeds inwardly and forms a deep groove 8 in the form of an annular depression, which is followed on the outside by means of a bent edge 9 by a plane bottom surface 10. The latter merges to the outside by a segmentshaped final surface 1 1 into a cylindrical casing part 12.

The central opening 4 serves for the reception and guidance of a primer 13, whose shoulder 14 abuts against the bent edge 5. Thus, a fixing of the primer 13 as against the cartridge bottom 3 has been assured. The firing contact 15 of the primer 13 is, as is well known, insulated against the primer housing consisting of metal.

So that the contact for the mass between the housing of the primer 13 and the gun chamber 1 is established, provision has been made for insertion of a metal band 16 into the central opening 4 and to shift it by means of the cartridge bottom 3 up to a ring 17 made of metal foil and fitting against the casing part 12.

As can be seen in FIG. 1, the middle part of the cartridge bottom 3 projects with the primer l3 beyond the periphery of the gun chamber 1 whenever the breach is opened. In the case of a sliding wedge-type breach block 18 with the ignition contact 19, which moves transversely to the axis of the barrel along a slanting plane toward the gun chamber 1, the projecting parts of the cartridge bottom 3 with the primer 13 being pressed back somewhat against the resistance of the spring force inherent in the cartridge bottom 3 until the sliding wedge-type breach block 18 fits against the gun barrel enclosing the gun chamber 1. At the same time, a solid contact between the firing contacts 15 and 19 occurs and also a connection of the mass of the sliding wedge-type breach block 18 with the gun barrel, so that the ignition of the primer 13, and thus the cartridge charge 2, can be triggered. This firing position is shown in FIG. 2.

We claim:

1. Combustible cartridge provided with an electric primer comprising a bottom portion of easily combustible synthetic material having a plurality of annular surfaces which are arranged in different planes in relation to one another and which are resilient, and a primer in the bottom portion developing a resistance against a firing contact of the weapon, said resistance being provided by the resiliency of the cartridge bottom portion.

2. Combustible cartridge according to claim 1, in which the cartridge bottom portion is provided with a central opening extending inwardly in the shape of a casing and which is followed first by at a bent edge by a funnel-shaped annular surface, then by a further bent edge and then a groove in the shape of an annular depression, and finally a bent edge adjacent a plane bottom surface which passes over on its part to an arc-shaped end surface and merges into a cylindrical casing part.

3. Combustible cartridge according to claim 1, in which the cartridge bottom portion is provided with a central opening extending inwardly in the shape of a casing and which is followed first by at a bent edge by a funnel-shaped annular surface, then by a further bent edge and then a groove in the shape of an annular depression, and finally a bent edge adjacent a plane bottom surface which passes over on its part to an arc-shaped end surface and merges into a cylindrical casing part, and in which the central opening is adapted to receive and guide the primer so that the bent edge lying between the central opening and the funnel-shaped annular surface serves as a stop for the primer which latter is provided with a collar.

4. Combustible cartridge according to claim 1, in which the cartridge bottom portion is provided with a central opening extending inwardly in the shape of a casing and which is followed fir'st by a bent edge by a funnel-shaped annular surface, then by a further bent edge and then a groove in the shape of an annular depression, and finally a bent edge adjacent a plane bottom surface which passes over on its part to an arc-shaped end surface and merges into a cylindrical casing part, and in which the central opening is adapted to receive and guide the primer so that the bent edge lying between the central opening and the funnel-shaped annular surface serves as a stop for the primer which latter is provided with a collar, and in which for the establishment of a contact of the mass between the primer and a gun chamber, a metal band is provided connected with the primer inserted in the central opening, said band extending across the cartridge bottom up to a ring made of metal foil and fitting on the outside against the side of the bottom portion. 

1. Combustible cartridge provided with an electric primer comprising a bottom portion of easily combustible synthetic material having a plurality of annular surfaces which are arranged in different planes in relation to one another and which are resilient, and a primer in the bottom portion developing a resistance against a firing contact of the weapon, said resistance being provided by the resiliency of the cartridge bottom portion.
 2. Combustible cartridge according to claim 1, in which the cartridge bottom portion is provided with a central opening extending inwardly in the shape of a casing and which is followed first by at a bent edge by a funnel-shaped annular surface, then by a further bent edge and then a groove in the shape of an annular depression, and finally a bent edge adjacent a plane bottom surface which passes over on its part to an arc-shaped end surface and merges into a cylindrical casing part.
 3. Combustible cartridge according to claim 1, in which the cartridge bottom portion is provided with a central opening extending inwardly in the shape of a casing and which is followed first by at a bent edge by a funnel-shaped annular surface, then by a further bent edge and then a groove in the shape of an annular depression, and finally a bent edge adjacent a plane bottom surface which passes over on its part to an arc-shaped end surface and merges into a cylindrical casing part, and in which the central opening is adapted to receive and guide the primer so that the bent edge lying between the central opening and the funnel-shaped annular surface serves as a stop for the primer which latter is provided with a collar.
 4. Combustible cartridge according to claim 1, in which the cartridge bottom portion is provided with a central opening extending inwardly in the shape of a casing and which is followed first by a bent edge by a funnel-shaped annular surface, then by a further bent edge and then a groove in the shape of an annular depression, and finally a bent edge adjacent a plane bottom surface which passes over on its part to an arc-shaped end surface and merges into a cylindrical casing part, and in which the central opening is adapted to receive and guide the primer so that the bent edge lying between the central opening and the funnel-shaped annular surface serves as a stop for the primer which latter is provided with a collar, and in which for the establishment of a contact of the mass between the primer and a gun chamber, a metal band is provided connected with the primer inserted in the central opening, said band extending across the cartridge bottom up to a ring made of metal foil and fitting on the outside against the side of the bottom portion. 